A Practice Note explaining how a defendant in a Pennsylvania court of common pleas civil case may assert affirmative claims against the plaintiff (counterclaims) or other co-defendants (cross-claims). This Note discusses the types of counterclaims and cross-claims a defendant may plead and identifies key considerations when drafting, filing, and serving an answer asserting counterclaims or cross-claims. This Note also addresses how parties may respond to counterclaims or cross-claims.